I have done this to a couple of cars. You don't touch the outer wheel well or quarter. All your doing is moving the inner over against the frame. I would get the spring relocation kit & move the springs. This will give you an extra 3 in. On a dart that I had, with all that done I had 15x10 wheels w/ 5 in. back spacing. 325x50x15 tires. Looked really good. I can give you an idea of what you gonna need to do if you wish. PS. you are gonna have to cut the spot welds on the trunk bracket.
